This paper presents the performance analysis of direct sequence ultrawideband (DS-UWB) systems operating with non-linear receiver front-ends. Following this analysis, we propose the novel use of pulse doublets to mitigate nonlinearity induced distortion. The signal to noise and distortion ratio (SNDR) and bit error rate (BER) were evaluated with varying degrees of non-linearity and interference power. The simulation results indicate significant performance improvements by using pulse doublets under high interference power and non-linear operating conditions. Utilizing pulse doublets allow reduced front-end linearity requirements and enable improvements in more critical circuit parameters. Front-end modules such as low noise amplifiers (LNAs), mixers and baseband amplifiers are designed using Peregrine's 0.5μm SOS-CMOS process to demonstrate the benefits of circuits designed with relaxed linearity requirements. The simulation results obtained using the Cadence Spectre RF simulator indicated that the sub-linear front-end achieved 33 dB increase in voltage gain, 2 dB improvement in noise figure, 64% saving in power and 917 MHz extension in bandwidth over its more linear counterpart.
|Number of pages||6|
|Journal||IEEE Wireless Communications and Networking Conference, WCNC|
|Publication status||Published - 2005|